Virtual Science Lab (VSL) An Educational Web
Application for Demonstrating Science Experiments
Daniel C. Doolan, Member, IEEE, IEE, BCS, Sabin. Tabirca, Colm O’Sullivan FInstP, CPhys
Abstract —This paper describes an application designed to
aid students learn about some of the fundamental theories of
science in their own time without the need for recreating
experiments in the lab. It allows the student to visually
ascertain the relationship between the video of the experiment
and the associated data recorded in real time. Interpretation
of the recorded data may prove difficult to understand, hence
the need for a visualization process. By combining the video
and recorded data into one application a student can readily
associate a particular visual cue from the video with that of
the recorded data.
Keywords — Animation,
Framework, Science, Video.
Education,
Java
Media
I. INTRODUCTION
C
lassroom use of Information and Communication
Technology (ICT) for teaching science and
technology has increased dramatically in recent years and
has proved to be a very effective tool in a variety of
situations. In particular, computers equipped with lowcost data acquisition systems (sometimes known as
‘dataloggers’) have had the effect of increasing the level of
hands-on experimental activity in science laboratories at
both secondary school and university. Supported by a
variety of sensors such as voltage, current, light, force and
temperature, these systems have been shown to be
pedagogically effective, particularly where higher level
learning skills are concerned [1] - [4]. The most popular
commercially available low-cost data acquisition systems
include those supplied by the US companies Vernier [5]
and PASCO [6] and the European systems CoachLab [7]
and ComLab [8].
Pupils’ understanding of basic principles can be
significantly improved by the use of such utilities in an
interactive and ‘hands-on’ manner. In many situations,
however, it is not possible for all students to be able to
perform every experiment that the teacher would like. In
such circumstances considerable pedagogical gain can be
Daniel C. Doolan is with the Department of Computer Science,
University College Cork, Ireland (phone: +353-21-490-3662; fax: +35321-427-4390; e-mail: d.doolan@cs.ucc.ie).
Sabin Tabirca is with the Department of Computer Science,
University College Cork, Ireland (phone: +353-21-490-3662; fax: +35321-427-4390; e-mail: tabirca@cs.ucc.ie).
Colm O’Sullivan is with the Department of Physics, University
College Cork, Ireland (phone: +353-21-490-2390; fax: +353-21-4276949; e-mail: ctosull@ucc.ie).
achieved by playing a recorded video of an experiment
while simultaneously and synchronously displaying the
data being accumulated on a computer screen. Some, but
by no means all, of commercially available data acquisition
systems allow a facility for user recorded video clips but
do not allow importation of data from other systems.
All such systems, on the other hand, have a feature that
allows the export of recorded data in the form of a text file.
While the data format is identical in all cases the header
information (for example: quantity / scale) is not. The
differences between systems are small, however, allowing
the user to easily edit a text file to a specified format.
The principle reason for the development of this system
came in the form of a request from the Department of
Physics at University College Cork. They required a tool
that would allow for the viewing of video footage taken of
an experiment and graphically display the associated
sensor readings recorded by a data acquisition system at
the same time. The main requirement was for a simple to
use application that required little training, so that students
in particular, could readily view an experiment and
associated data at any time.
The initial requirements of the application were to allow
for the playback of the recorded video and the
synchronised animation of the associated recorded data. It
was also requested that the system be cross platform as
currently the majority of university students have access to
computers, not all of which run the same type of operating
system.
The final request was for the application to be capable
of running from a web-page. This would allow for the
integration with online lab and lecture content. The web
based system ensures that further version updates of the
application would only require the modification of the
executable files at one location (the web-server). The
advantage of this is that students would not have to
upgrade their version of the application as updated
versions become available. As some student s personal
computers may not have an Internet connection, it was
necessary for the system to run as a standalone application.
It was also envisaged that the utility would have
applications in the context of physics lectures and
laboratories involving large numbers of students.
II. MULTIMEDIA TEACHING TOOLS
III. BUILDING THE APPLICATION
The use of the Java programming language as the
development system of choice for multimedia teaching
tools is becoming all the more prevalent. Many universities
are now using Java Applets to produce interactive
simulations of experiments that may be deployed online on
the respective course website [12][13][14]. This allows the
students to interact and learn in their own time with out the
pressures of classroom learning. Recent years has seen the
widespread use of multimedia for the purpose of teaching.
The current state of the application has four distinct
sections, each designated within its own Panel of a
JTabbedPane layout. The four sections are: “Viewer”,
“Synchronization”, “Manual Animation” and “Paste Data”.
The ``Viewer'' section simply allows for the synchronized
playback of the video and graphical representation of the
corresponding
acquired
sensor
data.
The
“Synchronization” section allows for the modification of
the rate of delay between subsequent frames of the
graphical animation. This feature was added as sometimes
the animation may not match perfectly with the video, and
this feature gives the user the facility to re-synchronise.
The “Manual Animation” section allows the user to
interactively scroll through the video playback and the
graphical animation. This is probably the most useful
section as users can control the animation rate themselves.
As is often the case with many experiments the point of
interest may last for mere milliseconds and so it is
necessary to be able to examine the relationship between
the video and the acquired sensor data moment by
moment. The final section “Paste Data” allows the users of
the data acquisition system to directly copy sensor data
directly from the acquisition system and paste it into the
VPL application. This allows them to immediately observe
the visualisation of the sensor data.
In “Multimedia in Physics Education in France” N.
Lebrun [10] discusses the use of multimedia for not just
Physics, but for other disciplines such as mathematics,
chemistry and biology. Clearly the use of multimedia has a
huge range of scientific benefits in terms of teaching.
Esquembre F. [11] “Easy Java Simulations” developed a
Java based software tool. It was designed and created by
science teachers, for science teachers and students alike.
One of the chief aims of such tools is to “Lower the
technical level required”, thus making technical content
accessible to a wider audience. It is also essential that the
software be fit for the purpose in terms of “size and effort”
required interaction.
The use of interactive tools is of tremendous benefit to
students who partake in distance learning courses.
Laboratory activities are typically the greatest restriction in
terms of distance learning. Hence the need for simple tools
that can simulate the physical lab experiments are essential
for such students. Nancheva et al. [15] again use Java
Applets to achieve this. This project involved the
development of eighteen independent applets for the
visualization of phenomena relating a several differing
research areas, such as: Atomic and Nuclear Physics,
Mechanics and Optics. Many online interactive applets are
available on the Internet, two examples [16] [17] cover
about a dozen application areas.
Jones. P [18] discusses an application called “World in
Motion” (now known as “Physics Toolkit” [20]) which is
designed to produce a set of graphs based on the video
input. The graphs are produced by marking key positions
on the video for key events. This contrasts with our
application (which animates graph data to video), but
shows that video is becoming a key element for carrying
out experiments.
Clearly the combined use of graphical animation in
conjunction with video will allow students to understand
far more readily the physical experiment. The use of the
Internet for dissemination [19] puts the physics lab in the
hands of distant learners. Without such resources distance
learners understanding of experiments would be severely
hindered.
A. The “Viewer” Section
This was the first section of the application to be
constructed. Initially just a simple structure was
established to allow for the playback of video using the
Java Media Framework package Fig. 2 [9]. With video
playback established the next stage was to focus on the
reading in of the sensor data.
Vin0 Vin7
t
V
Force
ms V
Newtons
0.0 0.005 2.534
1.0 0.005 2.534
2.0 0.005 2.534
3.0 0.005 2.534
4.0 0.005 2.534
5.0 0.005 2.534
6.0 0.005 2.534
7.0 0.005 2.534
8.0 0.004 2.534
9.0 0.005 2.534
10.0 0.005 2.534
Fig: 1. Data acquisition output file
Firstly to do this it was necessary to understand the
format of the data acquisition file. In the simplest of
experiments there would only be two columns of data. The
first relates to time, this could be in milliseconds, seconds,
minutes, or perhaps even hours for longer experiments. For
the majority of experiments the time duration is usually
within the remit of milliseconds to seconds. The second
column of the data file is the actual sensor data. The
addition of more sensors would simply add additional
sensor data columns in succession. At the top of the file
three rows of header information are required (This header
information may vary across some of the commercially
available dataloggers, and would need to be edited
accordingly). In the case of the time column it denotes
what the time increment is. In the case of sensor data
columns a textual guide is given to indicate what type of
sensor data the column contains. A typical example of such
a data file can be seen in Fig. 1, note the time in
milliseconds and the two sensors in operation (V in volts
and Force in Newtons). Typically the data acquisition
system is setup to record about 1,000 samples.
With the data acquisition sensor data available to the
application the progression to the graph visualisation could
occur. The graphical element is a Graphical Panel
produced by extending the JPanel class. Establishment of
the scaling factors for each axis was performed as follows:
for the (time) x axis:
graphWidth
nrSamples
For the y axis (sample data) the scaling factor is:
graphHt
graphMax − graphMin
display. This is of course only available if multiple sensor
data columns are included in the data file. This feature is
particularly useful, as students can add or remove graphs
as they see fit, and so gain an understanding of the interrelationship between the graphs. The final feature allows
the user to modify both the maximum and minimum levels
of each graph in the system. This allows the student to
modify the overall scales of the graphs so the graphs
produced are easier to interpret and appear similar to those
observed on the screen of the data acquisition system.
B. The “Sunchronisation” Section
The synchronisation section allows the student to
modify the delay period between particular times. With the
“Player” section the playback of the animation may drift
relative to that of the video. The synchronisation section is
a solution to this problem where by sections of the
animation can be speeded up or slowed down so the
experimental data fits synchronously with the on screen
video. The synchronization file that may be exported from
the application has only two columns of data Fig. 3. The
first being time and the second the sample point that
should be displayed for that particular time period. When a
synchronisation file is used to render the animation an
array of delays are calculated. A uniform delay is
generated between one synchronisation point and the next.
0.0
0.800532
1.8679081
3.1354173
3.9359494
4.4696375
5.070036
5.470302
6.00399
6.5376705
7.071366
7.4716305
7.738476
8.0053201
0
99
232
391
491
557
632
683
749
816
883
933
966
1000
Fig: 3. Synchronisation example data file
Fig: 2. “Viewer” application section screen shot
The process of animating the graph over time is carried
out by repainting the graphic area after a predetermined
delay, initially established from the data acquisition file.
The file has in its header the time value for example: ms
(milliseconds), s (seconds), m (minutes). So by examining
this data field and the difference between the first time
interval and the second the delay for the animation can be
established. As the animation is being run a certain amount
of time is required to calculate the next frame of the
animation and this time must be deducted from the delay
period to ensure synchronisation.
The remaining features of the “Viewer” section allow
the user to select the number of graphs they wish to
Fig: 4. “Synchronisation Section” screen shot
The synchronisation section provides an easy to use
interface to allow the student to modify the animation
delay Fig. 4. By dragging the slider at the bottom the
student may view the video, as the slider is dragged the
corresponding sample is displayed. The student can then
select a sample more suited to the video synchronisation
point and clicking the “Add” button to add the new
synchronisation point to the list of synchronisation points.
C. The “Manual Play” Section
The “Manual Play” section was developed to allow the
user full control over the synchronisation of the animation
and video Fig. 5 and 6. The student using the application
can set the precise moment at which the video should start,
as well as the precise time when the animation should
begin. The user can then control the playback via a slider
providing full control over the rate of animation.
students the teacher need not spend significant time editing
the video footage to begin at the precise time the
experiment begins and data is acquired from the sensors.
As the student has full control over the playback system
he/she can study all the nuances closely and observe all the
relationships between the graphs and video.
Movement of the Video Offset slider will modify the
“offset” at which the video will being playing (this is
measured in frames), likewise for the Animation Offset
“animoffset”. When the user plays the synchronised video
and animation by moving the appropriate slider the
required video frame to display is calculated as:
 sliderLoc

videoTime = 
× (nrFrames − offset ) + offset
nrSamples


Note the sliderLoc variable is the sample number that
should be currently displayed. The calculation for the
current position of the animation is:
sliderLoc 

 1−

nrSamples
 , nextFr > 0
nextFr = nrSamples × 

animOffset 
 1 − nrFrames 


D. The “Paste” Section
The ``Paste'' section is the simplest part of the program
but is an extremely useful feature for users of a data
acquisition system that has appropriate header information.
It allows them to directly copy and paste the acquired data
directly into the VSL application. Results may be
visualised immediately, doing away with the intermediate
stage of having to save the acquired data to disk before
importing it into the VSL program.
Fig: 5. “Manual Play” at beginning
Fig: 7: “Paste Section” screen shot
Fig: 6. “Manual Play” with animation
This feature is very useful if the video has some
unwanted footage at the start as the user can go right to the
point of interest and forget about the unnecessary footage.
It also means that when the footage is being prepared for
IV. TESTING
REFERENCES
The application was tested using a selection of sample
videos and data acquisition files. In general the application
executed well and lived up to its expectations. From the
learning point of view the “`Manual Play” section is of
greatest benefit to students as they can examine both the
animated graph and video at their own pace. It has been
shown to be a very useful tool, and will be used by
lecturers during class to aid in explaining concepts that
would otherwise be far more difficult to explain without
the aid of such visual cues as video and synchronised
graphical representations of the experiment as it occurred
in real time.
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
V. SUMMARY AND CONCLUSIONS
A Java based application has been successfully
developed to aid students learning of the essential
principles of science. From initial tests of students using
the application they were more readily able to grapple with
concepts that traditionally often caused significant
confusion. In particular, it should facilitate students
understanding of how graphs and mathematical functions
are used in physics to “tell a story”. The application was
designed to work with data from the Vernier acquisition
system. In the future it is envisaged that the system will
work with datasets from other vendors. It is hoped that the
application will be deployed and integrated into the
teaching system of the Physics Department in future years
and will prove to be a valuable tool to aid students in their
understanding of the fundamentals of the exciting world of
science.
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
ACKNOWLEDGMENT
[19]
Data for testing the application was acquired using the
e-ProLab system which was developed under the EU
Leonardo da Vinci Community Vocational Training
Action Programme, project SI143008 Computerised
Laboratory in Science and Technology Teaching
(ComLab-SciTech). Research funding source: “Irish
Research Council for Science, Engineering and
Technology”, funded by the “National Development Plan”.
The authors would like to thank Pat Twomey and John
O’Riordan of the Department of Physics, UCC for their
help in performing the experiments and testing the
application.
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